Cortical lesions at diagnosis predict cognitive impairment 20 years later

The number of cortical lesions at MS diagnosis accurately discriminates between the presence of absence of cognitive impairment after 20 years.

Study looked into how CLs at MS diagnosis could predict CI after 20 years of disease

CLs are one of the hallmarks of the MS course, with a prevalence that could even exceed that of white matter laesions. CLs reflect brain damage from the early stages of the disease, are cross-sectionally associated with clinical disability, and are responsible for MS progression. However, the long-term prognostic value of early CLs with regard to cognitive impairment (CI) is still unclear. As Dr Stefano Ziccardi (University of Verona, Italy) explained, this study aimed to investigate to what extent CLs at MS diagnosis could predict CI after 20 years of disease activity.

A total of 170 RRMS patients with about 20 years of follow-up since the clinical onset were included. They underwent a 1.5T MRI with Double Inversion Recovery (DIR) sequence within 3 years from the diagnosis MS, followed by periodic neurologic evaluations, MRI scans, and extensive neuropsychological assessment at the end of the study by using the Brief Repeatable Battery of Neuropsychological Tests (BRB-NT) and the Stroop Test (ST).

Early evaluation of CLs should be done in MS patients

Patients were classified by number of CLs at diagnosis (0 CLs, 1–2 CLs, or ≥3 CLs), and by cognitive status (normal or impaired) at follow-up. At baseline, of 170 RRMS patients 41% had 0 CLs, 19% had 1–2 CLs, and 40% had ≥3 CLs. At follow-up, mean EDSS had gone up from 1.5 to 3.0. Half of the patients were classified as cognitive normal, 25% as mildly cognitive impaired, and 25% as severely cognitive impaired. “Patients with cognitive impairment at follow-up had a significantly higher number of CLs: 2.5 vs 7.0”, observed Dr Ziccardi.

Furthermore, the number of CLs had a significant predictive effect on the risk of cognitive impairment 20 years later. Specifically, having ≥3 CLs at baseline was associated with an odds ratio for cognitive impairment of 3.70 (95% CI 1.8–7.5; p<0.001). The accuracy, specificity and specificity of the logistic regression model used was 65%, 75%, and 55%, respectively. “Early evaluation of CLs should be done in MS patients to anticipate the manifestation of cognitive problems”, said Dr Ziccardi, “in order to improve the monitoring of cognition and the diagnosis of CI, enabling prompt interventions.”